Intro stoichiometry. 1. Which pair of formulas represents the empirical formula and the molecular formula of a compound?

Transcription

1 Name: ate: 1. Which pair of formulas represents the empirical formula and the molecular formula of a compound? 1.. H 2 O, 4 H 6 O 4. HO, 6 H 12 O 6. H 4, 5 H 12. H 2, 3 H 6 2. compound contains 40% calcium, 12% carbon, and 48% oxygen by mass. What is the empirical formula of this compound? 2.. ao 3. a 2 O 4. a 3 O 6. ao 2 3. compound contains 0.5 mole of sodium, 0.5 mole of nitrogen, and 1.0 mole of hydrogen. The empirical formula of the compound is 3.. NaNH. Na 2 NH. NaNH 2. Na(NH) 2 4. compound is 92.3% carbon and 7.7% hydrogen. The empirical formula of this compound is 4.. H. H 2. H 3. H 4 5. Which represents both an empirical and a molecular formula? 5.. P 2 O 5. N 2 O 4. 3 H 6. 6 H 12 O 6 6. compound contains 40% calcium, 12% carbon, and 48% oxygen by mass. What is the empirical formula of this compound? 6.. ao 3. a 2 O 4. a 3 O 6. ao 2 page 1

2 7. The molecular mass of a compound of carbon and hydrogen is 42. Its empirical formula is 7.. H. H 2. H 3. H 4 8. compound consists of 85.7% carbon and 14.3% hydrogen by mass. Its empirical formula is 8.. H. H 2. H 3. H 4 9. compound contains 57% sulfur and 43% oxygen by mass. What is the empirical formula of this compound? 9.. SO. SO 2. SO 3. S 2 O The empirical formula of a compound is H 2. Which molecular formula is correctly paired with a structural formula for this compound? H 4. 2 H 4. 2 H 4. 3 H 8 E. 3 H 8 page 2

3 11. Given two formulas representing the same compound: 11. Formula Formula H 3 2 H 6 Which statement describes these formulas?. Formulas and are both empirical.. Formulas and are both molecular.. Formula is empirical, and formula is molecular.. Formula is molecular, and formula is empirical. 12. The percent by mass of oxygen in O is approximately %. 57%. 43%. 17% 13. What is the percent by mass of hydrogen in NH 3 (formula mass = 17.0)? %. 17.6%. 21.4%. 82.4% 14. The percent by mass of nitrogen in Mg(N) 2 is equal to The percent by mass of carbon in O 2 (g) is equal to page 3

4 16. The percent by mass of aluminum in l 2 O 3 is approximately The percent by mass of nitrogen in N 2 O is What is the percent by mass of hydrogen in H 3 OOH (formula mass = 60)? %. 5.0%. 6.7%. 7.1% gram sample of hydrated salt is heated to a constant mass of 0.80 gram. What was the percent by mass of water contained in the original sample? What is the total mass of oxygen in 1.00 mole of l 2 (ro 4 ) 3? g. 112 g g g 21. hydrated salt is a solid that includes water molecules within its crystal structure. student heated a 9.10-gram sample of a hydrated salt to a constant mass of 5.41 grams. What percent by mass of water did the salt contain? %. 16.8%. 40.5%. 59.5% page 4

5 22. What is the percent by mass of oxygen in propanal, H 3 H 2 HO? %. 27.6%. 38.1%. 62.1% 23. The percent composition by mass of magnesium in Mgr 2 (gram-formula mass = 184 grams/mole) is equal to Which equation represents a substitution reaction? H 4 + H 2 2 H 6. H 4 + 2O 2 O 2 + 2H 2 O. 3 H 8 + l 2 3 H 7 l + Hl. 4 H 8 + r 2 4 H 8 r Given the reaction: 25. 2X + r 2 O 3 X 2 O 3 + 2r The metal represented by X in the equation could be. Pb. Sn. Ni. l 26. In the balanced equation: 26. H 3 PO 4 (aq) + NH 3 (aq) X(aq) + NH 4 + (aq), the particle represented by X(aq) is. H 2 PO 4 (aq). HPO 4 2 (aq). PO 4 3 (aq). H 3 PO 4 (aq) page 5

6 27. Given the reaction: H 2 + 2H 2 2 H 6 This reaction represents. substitution. addition. esterification. saponification 28. Which equation represents a double replacement reaction? Na + 2 H 2 O 2 NaOH + H 2. ao 3 ao + O 2. LiOH + Hl Lil + H 2 O. H O 2 O H 2 O 29. Given the reaction: 29. Mg(s) + 2gNO 3 (aq) Mg(NO 3 ) 2 (aq) + 2g(s) Which type of reaction is represented?. single replacement. double replacement. synthesis. decomposition 30. ase your answer(s) to the following question(s) on the balanced chemical equation below H 2 O 2H 2 + O 2 What type of reaction does this equation represent? page 6

7 31. ase your answer(s) to the following question(s) on the information below. 31. Given the reaction between 1-butene and chlorine gas: 4 H 8 + l 2 4 H 8 l 2 Which type of chemical reaction is represented by this equation? 32. Given the balanced equation: 32. gno 3 (aq) + Nal(aq) NaNO 3 (aq) + gl(s) This reaction is classified as. synthesis. decomposition. single replacement. double replacement 33. Given the balanced equation: 33. 2KlO 3 2Kl + 3O 2 Which type of reaction is represented by this equation?. synthesis. decomposition. single replacement. double replacement 34. Given the incomplete equation for the combustion of ethane: H 6 + 7O 2 4O What is the formula of the missing product?. H 3 OH. HOOH. H 2 O. H 2 O 2 page 7

8 35. Which list includes three types of chemical reactions? 35.. condensation, double replacement, and sublimation. condensation, solidification, and synthesis. decomposition, double replacement, and synthesis. decomposition, solidification, and sublimation 36. Given the balanced equation representing a reaction: 36. H 2 SO 4 (aq) + 2KOH(aq) K 2 SO 4 (aq) + 2H 2 O(l) Which type of reaction is represented by this equation?. decomposition. neutralization. single replacement. synthesis page 8

9 37. ase your answer(s) to the following question(s) on the information below. In a laboratory, mole of colorless hydrogen iodide gas at room temperature is placed in a 1.00-liter flask. The flask is sealed and warmed, causing the HI(g) to start decomposing to H 2 (g) and I 2 (g). Then the temperature of the contents of the flask is kept constant. 37. uring this reaction, the contents of the flask change to a pale purple-colored mixture of HI(g), H 2 (g), and I 2 (g). When the color of the mixture in the flask stops changing, the concentration of I 2 (g) is determined to be mole per liter. The relationship between concentration and time for the reactant and products is shown in the graph below. Write a balanced equation to represent the decomposition reaction occurring in the flask. page 9

10 38. Given the balanced particle-diagram equation: 38. Which statement describes the type of change and the chemical properties of the product and reactants?. The equation represents a physical change, with the product and reactants having different chemical properties.. The equation represents a physical change, with the product and reactants having identical chemical properties.. The equation represents a chemical change, with the product and reactants having different chemical properties.. The equation represents a chemical change, with the product and reactants having identical chemical properties. 39. Which balanced equation represents a single-replacement reaction? 39.. Mg + 2gNO 3 Mg(NO 3 ) 2 + 2g. 2Mg + O 2 2MgO. MgO 3 MgO + O 2. Mgl 2 + 2gNO 3 2gl + Mg(NO 3 ) What is the mass in grams of 1.00 mole of O 2 gas? page 10

11 41. The gram molecular mass of a 3 (PO 4 ) 2 is g. 279 g. 310 g. 342 g 42. What is the gram molecular mass of calcium nitrate, a(no 3 ) 2? g. 150 g. 102 g g 43. What is the gram molecular mass of 1 mole of 3 H 5 (OH) 3? g. 58 g. 74 g. 92 g 44. Which substance has the greatest molecular mass? 44.. H 2 O 2. NO. F 4. I What is the gram formula mass of a(oh) 2? g. 34 g. 57 g. 74 g 46. What is the gram formula mass of a 3 (PO 4 ) 2? g. 214 g. 245 g g 47. One mole of O 2 has approximately the same mass as one mole of 47.. H 4. S. LiH. l 2 page 11

12 48. The gram-formula mass of (NH 4 ) 2 O 3 is g g g g 49. The gram formula mass of NH 4 l is g/mole g/mole g/mole g/mole 50. Show a correct numerical setup for calculating the formula mass of glucose, 6 H 12 O What is the percent composition by mass of sulfur in the compound MgSO 4 (gram-formula mass = 120. grams per mole)? %. 27%. 46%. 53% 52. What is the total number of moles of hydrogen in 1 mole of (NH 4 ) 2 HPO 4? What is the percent by mass of oxygen in magnesium oxide, MgO? %. 40%. 50%. 60% page 12

13 54. Given the unbalanced equation: 54. l 2 (SO 4 ) 3 + a(oh) 2 l(oh) 3 + aso 4 What is the coefficient in front of the aso 4 when the equation is completely balanced with the smallest whole-number coefficients? Given the unbalanced equation 55. r 0 + Sn 2+ r 3+ + Sn 0 What is the coefficient in front of the r 3+ when the equation is balanced using smallest whole-number coefficients? When the equation H 2 O 2 H 2 O + O 2 is completely balanced, the sum of all the coefficients will be Given the unbalanced equation: 57. 2MnO H + + l 2Mn H 2 O + l 2 What is the coefficient in front of the l when the equation is completely balanced using whole numbers? page 13

14 58. Given the reaction: 58. Fe 3+ + Sn 2+ Fe 2+ + Sn 4+ When the reaction is completely balanced using smallest whole numbers the coefficient of Fe 3+ will be When the equation NH 3 + O 2 N 2 + H 2 0 is completely balanced using the smallest whole numbers, the coefficient of the O 2 will be Given the unbalanced equation: 60. a 0 + l 3+ a 2+ + l 0 When the equation is completely balanced with the smallest whole-number coefficients, what is the coefficient of a 0? page 14

15 cces format version c Educide Software Licensed for use by Problem-ttic Intro stoichiometry 02/04/ decomposition, analysis, redox, endothermic, electrolysis cceptable answers include addition, chlorination, halogenation, redox, and synthesis. cceptable answers but not limited to: 2HI(g) H 2 (g) + I 2 (g) 2HI I 2 + H 2 20.

16 Teacher s Key Page (12.0) + 12(1.0) + 6(16.0)